Governor Rick Perry is a moron, by almost any account. But a far more dangerous personal affliction may have doomed him from the start: an inability to pee without singing folk songs. An exclusive excerpt from Politico's upcoming e-book Inside the Circus reveals a devastating bathroom anecdote that could capsize Perry's political career:

Virtually every Republican hopeful had his or her moment. Handsome and down-home, Rick Perry had once seemed a natural champion for the Tea Party pitchfork populism that prevailed in American politics on the eve of the primaries. But some knew better: in September, a close ally of Perry's had remarked to a friend that if Perry were smart, and if they had a couple of months to prepare, then they'd have a shot. The man added, "But he ain't, and we don't."

A bad back doomed any chance Perry stood to break through. It became an open secret that he was using painkillers in sufficient dosages to keep him standing through the two-hour debates. The manager of a rival campaign was at a urinal in an empty bathroom in Hanover, New Hampshire, before the Bloomberg News debate on October 11, when he heard someone come through the door loudly singing "I've Been Working on the Railroad." Wondering who was making all the noise, the campaign manager turned his head and saw, to his surprise, the governor of Texas. Perry came down the row of about twenty urinals and stood companionably close by. Nonplussed, the campaign manager made a hasty exit; as the bathroom door closed, he could hear Perry still merrily singing away: "I-I-I've been working on the ra-a-i-i-l-road, all-l-l the live-long day . . ."

Asked about the episode, a top campaign official said, "He whistles. I wouldn't read anything into it."